The present invention relates to motor-operated toothbrushes and relates more particularly to a bristle fastening structure for a motor-operated toothbrush which has a plurality of bundles of bristles fastened in a plurality of rotary wheels which are resiliently supported by a plurality of spring coils and driven by two rows of gears to carry said bundles of bristles to rotate and float thereon while cleaning the teeth.
Conventionally, a toothbrush generally comprises a handle having a brush head longitudinally disposed at one end with a plurality of bundles of bristles fixedly fastened therein. In recent years, various types of motor-operated toothbrushes have been disclosed. According to the known structures of motor-operated toothbrushes, the bundles of bristles are respectively fastened in rotary members and driven by a transmission device to rotate on their own axes respectively. Neither of the aforesaid toothbrush structures is satisfactory in use. Disadvantages of the aforesaid toothbrush structures are numerous and outlined hereinafter.
1. The gums may be injured easily during teeth cleaning process. For removing dirt from the gaps in the teeth, certain force must be applied to the bristles. Because no resilient means to support the bundles of bristles, the gums may be injured by the bristles easily when excessive force is applied thereto.
2. The bristles may be deformed and damaged easily. Because no resilient means to support the bundles of bristles, constantly rubbing the bristles against the teeth causes the bristles to deform quickly.
3. The enamel coating of teeth may be damaged easily when cleaning the teeth with excessive force.
4. Satisfactory cleaning effect is difficult to achieve. Because the bristles are fixedly or just rotatably fastened in the brush head, they can not be conveniently repeatedly moved in and out of the gaps in the teeth to thoroughly remove the dirt therefrom.